1. Field of the Invention
The present invention relates to a method and an apparatus for making uniform an aerosol concentration that changes with time of aerosol generation.
2. Description of the Related Art
Various methods for generating an aerosol containing solid powders or liquid droplets are currently known. In particular, generation of an aerosol from a solid powder is accomplished by a fluidized bed method, scraping of the powder packed in cylindrical shape, and the like. In generation of a powder aerosol, to uniformly maintain the concentration of powders in the aerosol, a uniform supply of source powders and an efficient conversion of the supplied source powders to an aerosol form are required.
However, according to currently available aerosol generation methods, an aerosol concentration is not constant over time. In detail, according to these methods, an average aerosol concentration over an extended period of time can be maintained constant, but it is very difficult to accomplish a short-term concentration stability of an aerosol.
In a process of using an aerosol, it is common to use solid powders or liquid droplets contained in the aerosol as a process material. In this regard, the concentration of the aerosol corresponds to the quantity of the process material. Therefore, uniform maintenance of the quantity of the process material with time by stabilization of the aerosol concentration is very important for process stabilization.
Therefore, a method for stabilizing an aerosol concentration that changes with time of aerosol generation is required.